ENDOGENOUS OPIOID-PEPTIDES AND MENTAL STRESS IN CONGESTIVE-HEART-FAILURE PATIENTS

Two groups of patients with acute congestive heart failure (CHF), New York Heart Association class III, presenting elevated plasma values of beta-endorphin, norepinephrine, atrial natriuretic factor (ANF) and e ndothelin-l, underwent the Mental Arithmetic Test (MAT) during placebo (n = 10) and naloxone hydrochloride (It = 10) infusion. The MAT durin g placebo significantly (p < 0.01) increased blood pressure, heart rat e, plasma levels of Met-enkephalin, dynorphin B, beta-endorphin, norep inephrine, ANF and endothelin-l. The increases in norepinephrine, ANF and hemodynamics after the MAT during naloxone infusion were higher (p < 0.01) than those during placebo, thus, the transient upregulation o f the endogenous opioid system during stress in CHF patients attenuate s the hemodynamic response by reducing norepinephrine release. (C) 199 8 Elsevier Science Inc.